Find Density Functions of X, Y, Z Variates

[iHeartof12]

The random variable X assumes the values 1,2,3 and 4 with equal probability. Find the density functions of the following variates:

Attempted solutions:

X 1 2 3 4
Pr(X) 1/4 1/4 1/4 1/4

a) Y=1-2X

Y -1 -3 -5 -7
Pr(Y) 1/4 1/4 1/4 1/4

b) Z= X/(X+1)

Z 1/2 2/3 3/4 4/5
Pr(Z) 1/4 1/4 1/4 1/4

Are my solutions for parts a and b correct?

 

[ArcanaNoir]

Yes, this is correct.

 

[iHeartof12]

Thank you. How'd your exam go today? I'm ready to get my exam over tomorrow I have a few more next week that I'm also studying for. Ahh the life of a college student. lol.

 

[ArcanaNoir]

It went fine except for one problem that made absolutely no sense to me. Don't forget to study the pdf of a random variable of a decreasing function, not just an increasing one. There was no extra credit :( But I guess that's what you get when you can do six and he'll grade your best five.